The U.S. could produce 40 percent of its electricity with rooftop solar

The United States could get almost 40 percent of its electricity from rooftop solar power, according to a new government agency report. For the first time since 2008, the National Renewable Energy Laboratory (NREL) has compiled zip code data to evaluate the cumulative photovoltaic potential of rooftops across the country, resulting in an estimated 1,118 gigawatts of clean energy. The report also sheds some light on which cities and states hold the most potential in terms of future solar power installations, which may or may not be a prediction of industry trends.

The NREL issued the new report (PDF) at the end of March, marking the first time since 2008 that national estimates of solar power potential have been calculated through such precise methods. The report is the culmination of three years of research, evaluating rooftops for their “suitability” for solar power generation. For a very simplified comparison, this is like using Google’s Project Sunroof on the entire country all at once, to get an idea of how much solar power could be produced if an array is placed on every rooftop that would be worthwhile.

Getting nearly 40 percent of a nation’s power from the sun is pretty impressive, especially for an energy hungry country like the U.S. However, many people think government leaders should be more aggressive about encouraging solar projects. Tesla and SpaceX CEO Elon Musk has repeatedly said that a few massive solar farms could power the entire country, but he doesn’t say a whole lot about the role of rooftop solar when it comes to supplementing the power grid.

In addition to tallying up solar potential across the nation, NREL also evaluated specific cities for their potential PV capacity and ranked them accordingly. Mission Viejo, California tops the charts with 88 percent solar potential rating. Close behind, Concord, New Hampshire is rated at 72 percent, and Buffalo, New York at 68 percent. It’s important to note that the top ranking six states on NREL’s solar potential list all have below-average energy consumption, suggesting that there continues to be a relationship between reducing usage and developing clean energy technologies toward the overall goal of cutting greenhouse gas emissions and preserving the environment.